Generator-motor power selection system



Feb. 9, 1,960

B. C. LIEBENTHAL GENERATOR-MOTOR POWER SELECTION SYSTEM 2 Sheets-Sheet 1 Filed July 16, 1955 w b @Si ASS mx. .Nw QQ ,Q AM Ul N/ y NR/ n A A Gum www @NGE QW NW @wh 1:1? NQSWLWWMI :Www A, ,A Gs V H J A A A A A n m A m m ue, ,Mw MV .U 4 l f www GN N9 .uw www A NQ, .AP N RG ATTORNEY Feb. 9, 1960 B. c. LlEBENTHAL 2,924,762

GENERATOR-MOTOR POWER SELECTION SYS-TEM Filed July 1e, 195e 2 Sheets-Sheet 2 heavy power.

United States Patent O M GENERATOR-MOTOR POWER SELECTION SYSTEM Benjamin C. Liebenthal, Downers Grove, Ill., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 16, 1956, Serial No. 598,101

4 Claims. (Cl. S18-151) This invention relates generally to electrical generatormotor power transmission systems and particularly to generator-motor power selection systems in which a plurality of engine-driven generator-motor sets are available for connection together in different combinations.

For many years little progress has been made in the oil drilling field in providing more flexible types of power. This may be partially explained, particularly during the early days of oil well drilling, by the fact that the operations were relatively small, the oil found was relatively close to the surface requiring only shallow Wells, and the demand for oil and the by-products thereof was rather easily met. Also, the drilling sites selected were quite accessible and usually located on fairly high, firm ground. With the tremendously increased demands for oil, however, such easily accessible sites and shallow well sources of oil in many instances have been exhausted or are no longer capable of supplying such demand. Oil wells are now being drilled to depths of over 25,000 feet (nearly live miles) in such undesirable sites as deep bays, bayous, swamp land, etc.

Because of the undesirable yconditions encountered in attempting to obtain oil to meet the increased demand, the heavy, cumbersome steam rigs previously used and still in extensive use are becoming more and more unsatisfactory. This is true not only because of the great amount of time needed to disassemble, move, and reassemble such rigs but also because of the relative inflexibility of the power supplied by them. Furthermore, these rigs-such as, steam and other types of enginedriven mechanical rigs--are often unreliable and it can be appreciated that where drilling operations are carried on below the surface of the earth as much as five miles should the rig fail, and the pipe in the hole be lost, for example, by freezing of the earth around the pipe when the rig stops turning it, or because the pipe is dropped from the turntable into the hole, literally hundreds of `thousands of dollars may be lost.

For the foregoing reasons there has been a pressing need for a more flexible type of motive power which has resulted in the adoption, to a large extent, by the oil drilling profession of diesel electric power. Diesel electric power has proven itself to be a substantial improvement over other types of power previously used. Heretofore, however, the power selection control systems used with diesel electric power have not always proven entirely satisfactory. This appears primarily to be due to the fact that the various loads requiring diesel electric power vary widely in their characteristics and the connections between the loads and the power supply on a drilling site in the 'past have been more or less permanent. There are usually three basic drilling operations which require One of these is the so-called draw works operation which primarily comprises pulling the pipe out of the hole to, for example, ychange the drilling bit on the lower end thereof, and then relowerng the pipe into the well after the bit `has been changed. Another of the operations is the actual drilling operation which com- 2,924,762 Patented Feb. 9, 1960 prises rotating the drilling table causing the drilling bit to cut through the various earth stratas encountered. A third heavy power operation is the driving of one or more mud pumps. These pumps serve to pump mud down through the center of the drilling pipe and up the sides so as to carry away the drillings and also lubricate the pipe as it turns in the hole. Normally, not more than two of these operations is carried on simultaneously. If, however, the power for any of the operations should fail at an inopportune time there is a great likelihood that the drill hole might be lost resulting in a financial loss of many thousands of dollars. It will be appreciated too that the loads for each of the operations naturally varies which indicates that greater power exibility would be desirable. For example, the table load will vary depending on the type of strata encountered during the drilling operation and also depending on the depth of the drilling operation. The same may be said for the mud pump operation. The draw works load will vary over a wide range depending on the amount of pipe in the hole at the time it is necessary to change the bit.

ln view of the wide variance in the various types of loads encountered and the always present danger of loss of equipment and time in the event of a power failure, this invention proposes an engine-driven generator-motor selection system which provides power for all operations at all times and which power is selective so that if one operation requires heavy power and another light power, the power can be properly distributed for the various power requirements by a simple selection.

The present invention also proposes to make the power selection flexible enough so that in the event power for one of the operations should fail the power of another operation, not then operating, may be transferred to the operation on which power failure has occurred.

This has all been accomplished by a unique generatormotor combination and selection control which provides the maximum exibility of power distribution and safety for the continuity of the drilling operations. This has all further been accomplished by the unique selector control system to be described in detail below without the requirements of any substantial amount of standby power.

For a more complete understanding of the invention and various operations thereof, reference is now directed to the drawing comprising Figures l and 1A which, when placed one above the other, represent a single schematic diagram of the unique generator-motor power selection system.

Referring now to the diagram, a pair vof series motors M1, M2 are shown connected in series with each other and are adapted to be connected by suitable coupling to the draw works which, as previously mentioned, is primarily for the purpose of raising and lowering of pipe out of and into the drilling hole. A second pair of series motors M3, M4 are shown connected in series with each other and also by suitable coupling are adapted to be connected to one or more mud pumps which, as previously explained, pump mud down through the pipe and up the outside `of the pipe so as to carry away the drillings, effect lubrication, etc. A single series motor M5 is also shown which may be coupled to the drilling table to peri a d in series with a separate exciting winding 4. Each exciter 2 in turn is excited by a iield winding 6 which derives its excitation current from an A.C. source shown as transmission lines 8, and one of several manually operated controls 23, 32 or 40, vto be described in greater detail shortly. Any one of these manuallyoperated controls is adapted to be connectedtoand control the output of a transformer 16 whose output is rectiiied by a rectifier 18, impressed across winding 6, and modulated by Vfeedback from the generator through a transductor Transductor 20 modulates A.C. currentv throng-ii the wires l2, 14 which-is rectified by a second rectiiier 22 and also impressed across yexciter winding 6 so as to (as already mentioned) modulate the output from controls 23, 32 or 40 and provide each generator with certain generator characteristics. Gnly one excitation control means has actually been shown which is for the generator lGl. This has been done for the purpose of simplifying thediagram. It is to be understood, however, that each ofthe generators `TG2, 2Gl and 2G2 is provided with an excitation means identical in every respect with the ex'- citation means shown for the generator' 1Gll. These excitation means are symbolically indicated by the references in the lower left-hand corner of -the diagram, AlGl representing the excitation control means for generator ilGl, A2G2 representing the excitation control means for generator 2G2, and soon.

As indicated in the lower right-hand corner of the drawing, a manually operated draw works control, so labeled and which has beenindicated by the numeral 23, is shown. This control 23 is electro-mechanical in nature and comprises a variable A.C. rheostat 24 connected across the A.C. source 8, 10 and a manually operated brush 26 connected by a wire conductor 28 to one or more switching wafers of a manually operated selector switch 30 tobe described in greater detail shortly` The numeral 32 refers to a mud pump control, so labeled, which is similar tothe control 23 in that it is also electro-mechanical and comprises a variable AC. rheostat 34 connected across the A.C. source li, 10 and including a brush-carrying -linger 36 connected by a wire conductor 38 to one or more of these switching wafers of the manually operated selector switch 30. A third manual control, indicated by a numeral 40, for the rotating-drill table which again is` electro-mechanical in nature also includes a variable AiC. rheostat 42 connected across A.C. Source S, 10 and a brush-carrying linger 44 connected by a conductor 46 and switch 48 to one or more of the switching wafers of the manual selector switch 30.

Referring now for a moment to the draw works motors MV1, M2, it will be observed that normallyopen power contactors H1G12G2, H1G2, H1G1 are provided between these motors and generators lGl, 2G21, generator 1G2 and generator 2G2, respectively. Similar normally open contactorsPlGZ, P1G12G2, and P1G22G1 are providedbetween mud pump motors M3, M4 and generator IGZ, generators TG1, 2G2 and generators 1G2, 2G1, respectively. Provided between the table motor M5 and generators 2G1 and 2G2 are contactors T2G1 and T2G2. Y

Located between the draw works control 23, the mud pump control 32 and table control 40 is the aforementioned selector switch 30. In the embodiment shown the selector switch 30 has four positions, an Off position,

` a tirst position, a second position and a third position,

(a load requiring heavy power) and that the table motor 755 will be used only to disconnect the threads ofthe pipe into its various sections (a light load), the operator will move the selector switch 30 from the Oil` to the No. l position. When the selector switch is placed in the No. 1 position current will be supplied from the A.C. source 8, 10 through a transformer 50 and a rectifier 52, through wafer W1 to a contact linger thereof, to a conductor 54, conductor 56, to energize contactors H1G12G2 and P1G2. Current will also be supplied through the finger of wafer W2 to conductor 58 thereby energizing contactor T2Gl. Energization of contactor H1G12G2 connects draw works motors M1, M2 across generators 1G1, 2G22. This will appear by beginning with the positive side of motor M2 and following through its winding, a conductor 60, one of the now closed interlocks of contactor HlGlZGZ, wire 62, wire 64, generator 2G2, wire 66, generator 1G1, wire 63, wire 70, the other now closed interlock of contactor H1G12G2 and wire 72 returning to the negative side of motor M1. Similarly,mud pump motors M3, M4 will oe connected across generator 1G2 by lclosure of contactor PlG2. This will appear by bef ginning ywith the positive side of mud pump motor M4 following conductors 74 Aand 76, one of the now closed interlocks of contactors P1G2, wire 78, generator lG2, wire 80, wire 66, wire 82, wire 84, wire S6, the other now closed interlock of contactor PlG2, wire 88 and wire 90 returning to the negative side of mud pump vmotor M3. Table motor M5 will be connected across generator 2G1 by closure of interlock TZGI, as indicated by beginning with the positive side of motor M5, following wire 91, one of the now closed interlocks of contactor T2G1, wire 84, wire 82, wire 66, wire 92, generator 2G1, wire 94, wire 96, and the now closed other interlock of contactor T261 and wire 98 leading to the negative side `of motor M5.

It is to be understood that when selector switch 30 is manually operated to its various positions it causes a shaft 100 thereof to turn along with ythe fingers associated with each of the wafers thereof, indicated by the symbols WIr-W8. Thus, with the draw works motors M1, M2 connected across generators 1G1, 2G2; mud pump motors M3, M4 connected across generator 1G2 and table motor M5 connected across generator 2G1 by turning selector switch 30 to the No. l position the manually operated draw works control 23 will be connected to the individual controls for each of generators 1G1, 2G2. This is accomplished as follows: When the selector switch 30 is placed in the No. 1 position the draw works control 23 is connected by wires 28, 102 and the linger of wafer W5 to the line 104, labeled A1G1, which represents the excitation controls for generator 1G1. The draw works control likewise is connected by wires 28, 105 and'ngers of wafer W6 to the excitation controls for generator 2G2 which controls are indicated by line 106 and labeled A2G2. The manually operated mud pump control 32 is connected by wires 38, 108 and linger of wafer W7 to wire 110 representing the controls of generator 1G2 symbolized by the reference character A1G2. The manually operated table control 40 is connected by wire 46 and switch 48, wire 112 and the linger of wafer W8 to wire 114 which represents the controls for generator 2G1 symbolized by the reference character A2G1.

From the foregoing description of the first operation of the generator-motor power selection system control it will be appreciated that by a single selection on the part of the operator he is automatically enabled to select the most suitable power distribution for the various oil drilling operations which system automatically coordinates the controls to each operation with the power selected for that operation.

Assuming now that the draw works operation has been completed and conditions aresuch that a heavy load demand is made on the mud pump motors M3, M4 the operator by first removing all the load on the generators 1G1, 1 G2, 2G1, 2G2 by returning the individual controls 23, 32 and 40 to their zero power positions can now make an additional selection by moving the selector switch 30 to the No. 2 position. Movement of selector switch 30 to the No. 2 position will by reason of movement of the fingers of switch wafers W1--W8 deenergize the contactors H1G12G2., P1G2 and T2G1 to disconnect the motors Ml-MS from the generators to which they were formerly connected. The individual controls 23, 32 and 40 also will be disconnected by these wafers from the controls of the generators to which they were formerly connected. Movement of the switch 30 to the No. 2 position will cause 'energization of contactors H1G2, P1G12G2 and T2G1. Energization of contactor H1G2 will connect motors M1, M2 across generator IGZ. This will appear by tracing the circuit beginning with the positive side of motor M2, following conductor 60, conductors 116, 118; one of the now closed interlocks of contactor H1G2, conductor 120, conductor 78, generator 1G2, conductor 80, conductor 66, conductor 82, conductor 84, the other now closed interlock of contactor H1G2 and conductors 122 and 72, returning to the negative side of motor M1. Closure of contactor P1G12G2 connects mud pump motors M3, M4 across generators 1G1, 2G2. The circuit comprises the positive side of motor M4, wire 74, the now closed interlock of contactor P1G12G2, wires 124, 62, 64, generator ZGZ, wire 66, generator 1G1, wire 68, wire 70, the other now closed interlock of contactor P1G12G2, wire 126, wires 88 and 90, returning to the negative side of motor M3. Since contactor T2G1 is again energized when the selector switch 30 is placed in the No. 2 position, motor M5 is connected across generator 2G1 by a circuit previously traced out. The movement of switch 30 to position No. 2 connects the draw works contnol 23 to the generator controls A1G2 of generator IGZ. This is accomplished via the wire 28, the finger of wafer W7, which is now moved to the next position clockwise. Mud pump control 32 is connected to the generator controls of generator 1G1, 2G2 via wires 38, 128, 130 and the fingers of wafers 5 and 6, which have now moved to the next position clockwise. The table control 40 is connected to the controls of generator 2G1 via the wire 46, switch 48, wires 112 and 132 and the finger of wafer W8, which is also moved to the next position clockwise.

If, now, the action of selector switch 30 is repeated for a change from position No. 2 to position No. 3 to change the generator and motor connections `and the manual control and generator control connections in a manner similar to the manner heretofore set forth, the draw works motors M1, M2 will be connected across generator 1G1, the mud pump motors M3, M4 will be connected across generators 1G2, 2G1 and table motor M5 will be connected across generator 2G2.

It is believed that in View of the previous explanations and tracing out of circuits that this will be appreciated without any further detailed description.

The latter position No. 3 might be selected, for example, in the case of a power failure for generator 1G1 during a heavy drilling operation when a great deal of mud is necessary in which event the generator 1G1 across which the mud pump motors M3, M4 were connected willbe disconnected therefrom and generators IGZ, 2G1 will be utilized to operate the mud pump motors.

From the foregoing description it may now be appreciated that a unique and extremely versatile and flexible power selection system has been provided for oil drilling oprations which provides flexibility in the power supplied for the various operations and also incorporates the safety feature of what amounts to a standby power without actually having to provide additional power plants for such standby power. The system is extremely simple for the operator to operate who merely has to make a selection :and then operates the controls for the various drilling operations.

What is claimed is:

1. A generator motor power selection system for an oil rig comprising a draw works motor, a mud pump motor and a rotating table motor, a first diesel engine, a first generator and a second generator driven by said first diesel engine, a second diesel engine, a third generator and a fourth generator driven by said second diesel engine, a manually operated electro-mechanical control associated with said draw works motor, a manually operated electromechanical control associated with said mud pump motor, a manually operated electro-mechanical control associated with said rotating table motor, control means for each of said generators, normally open sets of power contactors between said first and fourth generators and said draw works motor, normally open sets of power contactors between said second generator and said draw works motor, normally open sets of power contactors between said first generator and said draw works motor, a normally open set of power contactors between said second generator and said mud pump motor, normally open sets of contactors between said first and fourth generators and said mud pump motor, normally open sets of contactors between said second generator and said third generator and said mud pump motor, a normally open set of contactors between said third generator 4and said table motor, a normally open set `of contactors between said fourth generator and said table motor, manually operated selector switching means controlling the opeartion of said sets of contactors, and interposed between said manually operated electro-mechanical controls to selectively connect said generators to said motors and further operable to connect the manually operated electro-mechanical control associated with said draw works motor to the control means of the generator or generators connected by said selector means to said draw works motor, and to connect the manually operated electro-mechanical control associated with said mud pump motor to the control means of the generator or generators connected to said mud pump motor, and to connect the manually operated electromechanical control associated with said rotating table motor to the control means of the generator operatively connected to said table motor by said selector switching means.

2. A generator-motor power selection system for an oil drilling rig comprising a draw works motor, a mud pump motor, a drilling table motor, a first diesel engine, a first generator and a second generator driven by said first diesel engine, a third generator and a fourth generator driven by said second diesel engine, control means for each of said generators, a manually operated electro-mechanical control associated with said draw works motor, a manually operated electro-mechanical control Aassociated with said mud pump motor, a manually operated electro-mechanical control associated with said table motor, and manually operated multiple pole selector switching means operable to connect said generators to said motors in different combinations, said selector switching means including switches between said manual controls and the controls of said generators operable by said selector switching means to connect said control associated with one of said motors to the controls of the generators or generator to which the particular motor is connected by said selector switching means.

3. A generator-motor power selection system for an oil drilling rig comprising a first motor for a first load and a second motor for a second load, a first enginedriven generator including controls therefor, a second engine-driven generator including controls therefor, a manually operated electro-mechanical control for said first motor, a manually operated electro-mechanical control for said second motor, normally open contactors between said first motor and said first generator, normally open contactors between said first motor and said second generator, normally open contactors between said first generator and said second motor, normally open' contactors between said second generator and said second motor,vand generator-motor combination selectormeans manually operable to a firstposition to selectively energize certain of saidcontactors to connect the first of said generators to one of said motors and the second of said generators to the other of said motors and to connect the manual control for the iirst motor to the controls ofthe generator connected by said selector switching means to said first motor and to connect the manual control for said second motor to the control for the gen- .erator connected to said second motor.

4. A generator-motor power selection system for an oil drilling rig comprising arst motor for a first load and a second motor for a second load, avfirstlenginedriven generator .including control means therefor, a second engine-driven generator including control means therefor, a manually operated electro-mechanical control for said first motor, aV manually operated electro-rnechanical control for said second motor, normallyopen contactors between said first generator and said iirst motor, normally open contactorsbetween said second generator and said first motor, normally open contactors between said rst generator and said second motor, normally open contactors between said second generator and said second motor, andgenerator-motor combination selector means having a first position yand a` second position, saidselector means .being manually operable to said tirst positionto selectively energize the contactors between said first generator and said rst motor and the contactorsbetween said second generator and said second -motorto connect said first generatorto said first motor and said second vgenerator to said second motor and to connect the manual control for the firstmotor to said first .generator control means and to connect the manual control for said second motor to said second generator control means, said selector means being manually operable to a second position to selectivelyl deenergize the contactors between `said first generator and said iirst motor and the contactors between said second generator and said second motor and to disconnect the manual control for the iirst motor from the control means of said firstgenerator and to disconnect the manual control for said second motor from the control means of said second generator and to energize the contactors between said first generator and said second motor and the contactors between said second generator and said iirst motor and to connect-the manual control for the second motor to the control means of said first generator and to connect the manual controls for said first motor to the control means for said second generator.

References' Cited inthe file of this patent UNITED STATES PATENTS 2,026,600 Wilkinson Jan. 7, 1936 

